// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/message_loop/message_loop.h"
#include "base/win/wrapped_window_proc.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace {

DWORD kExceptionCode = 12345;
WPARAM kCrashMsg = 98765;

// A trivial WindowProc that generates an exception.
LRESULT CALLBACK TestWindowProc(HWND hwnd, UINT message,
    WPARAM wparam, LPARAM lparam)
{
    if (message == kCrashMsg)
        RaiseException(kExceptionCode, 0, 0, NULL);
    return DefWindowProc(hwnd, message, wparam, lparam);
}

// This class implements an exception filter that can be queried about a past
// exception.
class TestWrappedExceptionFiter {
public:
    TestWrappedExceptionFiter()
        : called_(false)
    {
        EXPECT_FALSE(s_filter_);
        s_filter_ = this;
    }

    ~TestWrappedExceptionFiter()
    {
        EXPECT_EQ(s_filter_, this);
        s_filter_ = NULL;
    }

    bool called()
    {
        return called_;
    }

    // The actual exception filter just records the exception.
    static int Filter(EXCEPTION_POINTERS* info)
    {
        EXPECT_FALSE(s_filter_->called_);
        if (info->ExceptionRecord->ExceptionCode == kExceptionCode)
            s_filter_->called_ = true;
        return EXCEPTION_EXECUTE_HANDLER;
    }

private:
    bool called_;
    static TestWrappedExceptionFiter* s_filter_;
};
TestWrappedExceptionFiter* TestWrappedExceptionFiter::s_filter_ = NULL;

} // namespace.

TEST(WrappedWindowProc, CatchesExceptions)
{
    HINSTANCE hinst = GetModuleHandle(NULL);
    std::wstring class_name(L"TestClass");

    WNDCLASS wc = { 0 };
    wc.lpfnWndProc = base::win::WrappedWindowProc<TestWindowProc>;
    wc.hInstance = hinst;
    wc.lpszClassName = class_name.c_str();
    RegisterClass(&wc);

    HWND window = CreateWindow(class_name.c_str(), 0, 0, 0, 0, 0, 0, HWND_MESSAGE,
        0, hinst, 0);
    ASSERT_TRUE(window);

    // Before generating the exception we make sure that the filter will see it.
    TestWrappedExceptionFiter wrapper;
    base::win::WinProcExceptionFilter old_filter = base::win::SetWinProcExceptionFilter(TestWrappedExceptionFiter::Filter);

    SendMessage(window, kCrashMsg, 0, 0);
    EXPECT_TRUE(wrapper.called());

    base::win::SetWinProcExceptionFilter(old_filter);
}
